Abstract
The physical properties of the new cubic phase of as well as of isomorphic and are studied using first-principles calculations. , , and are semiconductors with band gaps of 1.8, 1.1, and 0.6 eV, respectively. The band structure is characterized by the simultaneous presence of steep and extremely flat bands. The calculated shear modulus indicates that the cubic will be harder than the mononitride HfN. At ambient conditions, the cubic modifications of (, Zr, Ti) are metastable with respect to orthorhombic phases, but the orthorhombic phases of and are stable with respect to the mononitrides and nitrogen.
- Received 20 November 2002
DOI:https://doi.org/10.1103/PhysRevLett.90.125501
©2003 American Physical Society